Interatomic bonds and the tensile anisotropy of trialuminides in the elastic limit: A density functional study for Al3(Sc, Ti, V, Cr
- Author(s)
- Michal Jahnatek, Marian Krajci, Juergen Hafner
- Abstract
The tensile anisotropy in the elastic limit of Al3(Sc, Ti, V, Cr) intermetallic compounds in both the L12 and D022 crystal structure has been investigated using first-principles density-functional calculations. In both crystal structures the main bonding character comes from the saturation of dominant d3 (L12) and d4 (D022) hybrid orbitals located on the TM atoms. The series Al3Sc Al3V corresponds to gradual d-band filling and leads to a gradual increase of bond-strength and covalent bond formation. The magnetism of Cr breaks this trend in the Al3Cr compound (for both ferromagnetic and antiferromagnetic configurations). In this series, a trend towards an increased anisotropy of the elastic constants, Young modulus Y and Poisson ratio is observed. The easy and hard directions of tension can be simply identified by the variation of Y, which corresponds to the presence or absence of covalently bonded-Al-TM-chains. A high anisotropy of the Poisson ratio arises also from an alternation of atoms in the lateral directions and can be understood in the same terms.
- Organisation(s)
- Computational Materials Physics
- External organisation(s)
- Slovenian Academy of Sciences and Arts
- Journal
- Philosophical Magazine
- Volume
- 87
- Pages
- 1769-1794
- No. of pages
- 26
- ISSN
- 1478-6435
- DOI
- https://doi.org/10.1080/14786430601057946
- Publication date
- 2007
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 1030 Physics, Astronomy
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/a8f2fb55-ce18-40d9-9bbf-2317f8506ab9